Corksil

Hey I have B20vtec (b20z2 block/b16a3 head)

After a short drive, my top and bottom radiator hoses get pretty hard. it doesn't feel normal and ive got 6 odyssey vans and none of them are even close to that hard while running.

Here's what I have replaced already and I still have the problem...
- it's not the thermostat, because that's brand new and not in backwards
- it's not old hoses because the top/bottom radiator hoses are new
- it's not the radiator cap, because I replaced that with OEM honda today
- it's not the waterpump, because that is brand new GSR one i installed 10 miles ago
- it's not the head (it was pressure tested and decked at machine shop - all good)
- i don't think it's the headgasket because i just replaced it and torqued properly
- i don't think the radiator is plugged cuz it was brand new and flushed with degreaser after i did swap (hosed in the top, water came out bottom/vice-versa)

when the car idles for a few minutes, the thermostat opens and the bottom hose gets hot. this is normal and working.

anyone have ideas i'm losing my mind i will try anything! thanks HT

john666

i gotta ask,, okay so your hoses get hard.. any car problems ? i dont feel up my car hoses ever so i have no idea how soft or hard they get lol

DumpdEJ6

Well once the car gets up to operating temp, its going to cause pressure in the cooling system, so it sounds like normal operation to me.

Corksil

it feels like much more pressure than it should be in the hoses.

after a hard drive - the car doesn't want to idle. It idles really low and almost stalls before revving back up to around 400rpm. (I figured a b20v on un-tuned ECU will never run perfectly?)

thanks a lot guys i can't wait to get my baby on the road

Corksil

bump

Corksil

cmon guys...

Corksil

bumpweasel has occurred

Arthas

My hoses are always hard when the car is at normal operating temperature and I have a D16Y7 with the correct ECU.

Corksil

interesting find: when the hoses were exceptionally hard, and the motor was exceptionally hot - i started to unscrew the rad cap holding pressure down to stop it from exploding in my face.

when the cap was unscrewed, i slowwwwwly lifted it and when i got up a few MM there was a massive ejaculation of air into the overflow tank. I know it was air because it bubbled, instead of liquid which wouldn't bubble *durrrrR*

I think my radiator cap is not letting pressure (air) out of the cooling system and into the overflow tank for some reason. I dunno why, because its a brand new rad cap and i can't think of anything else...

i will be bringing the car up to operating temperature today, and then letting it blow the extra air into the reserve (by loosening cap and lifting it ever so slightly - not enough to let coolant out and burn me, but just to release air into the reserve..)

as an aside - i know that rad hoses get hard while the car is running and the cooling sys is under pressure. I manage a rental fleet of 6 honda odyssey vans, own two del slo's, and own a 2nd gen odyssey as well. I know how hard the hoses should feel under pressure, and mine feel much harder.

thats why im postings

thanks guys!

Arthas

Mine get super hard. I replaced them with silicone hoses though.

bandit67

With everything in the cooling system working at normal capacity, the radiator cap should be what sets the system pressure. In my old Chevys, I would run caps from 14 to 17 psi. I would think the stock Hondas would also be about 17 also. Try running different rad caps and see what the differences are. If the head gasket is leaking small amounts of compression into the system it will go to max psi fast. When the pressure exceeds nominal operating pressure , the cap starts dumping water/air. IF you are getting air in a known air bleed system........head gasket is probably leaking. If you have any head gasket leaking you will not be able to maintain a set level of coolant in the resivoir tank.

Juan Carlos 123

I know this is a very old thread, but for anybody reading having this problem, if your engine doesn't have an air bleeding
valve, you have air trapped in the heads. Seems logical that when you fill up your system, air will be pushed out by the
fluid coming in. This is not always the case. Some engines are tilted in a way, that water coming in will only push on
an air pocket, which when heated will produce steam, specially after you turn off the engine.
Air will be pushed out on any engine if it was under pressure. But it is not when you fill up.
I have fixed a few cars with this problem, when owners have been told "bad HG" by other shops.
Go ahead, call me crazy. You will not be the first one.

Badcopyinc

Just wanted to add in that i had bad radiator caps before, even brand new ones.

Juan Carlos 123

If I didn't know better I will call YOU crazy.
What brand did you use that solved your issue?
Slant or gates is the ones we use. No Honda, No Mopar, No OEM.

TomCat39

No Honda, No OEM..... When talking about a Honda car, OEM would be Honda, would it not?

Juan Carlos 123

No. What I meant was:
I do not use Honda.
I do not use Mopar,
I do not use Toyota.
I do not use AC Delco.
I do not use Subaru, etc.
I do not use OEM on rad caps.

TomCat39

I gotchya...

Being on a Honda site I tend to miss generalizations or broader scope comments.

My bad.

Dom T

I have a 2002 CRV with the same issue and I was told I have a small leak in the head gasket. The top hose gets very hard and the hose actually burst. The following day the radiator burst. There is no white smoke, no overheating and the car runs great until it blows up!